Metformin, though primarily an antidiabetic drug, has been found to play an important role in a variety of cutaneous disorders. Because of its role in improving hyperinsulinemia, it has proven beneficial in hormonal acne, hidradenitis suppurativa and acanthosis nigricans. Of late, use of metformin in psoriasis and cutaneous malignancies has shown promising results. In this chapter will throw light on these virtues of metformin.